Master sheet set for spirit duplicating



Feb. 16, 1960 D. LUNDBERG 2,925,033

MASTER SHEET SET FOR SPIRIT DUPLICATING Filed Nov. 5, 1956 V INVENTOR DON L UNDBER /4 ATTOR i MASTER SHEET SET FOR SPIRIT DUPLICATING Don linndberg, Irvington-on-Hudson, N.Y., assignor to Old Town Corporation, New York, N.Y.

Application November 5, 1956, Serial No. 620,307 1 Claim. (c1. nil-149.4

This invention relates to an improved master sheet set fbr use in spirit duplicating machines-Le. pre-assembled sets including a master-and a spirit carbon.

.Basically, the spirit duplicating method consists of pressing a copy sheet moistened with a spirit fluid or solvent against a mastersheet bearing a reversed carbon image on it. The moistened copy sheet dissolves off a small quantity of carbon from the master to produce a rectified copy of the carbon image.

The master sheet is usually prepared by placing a carbon sheet with its coated face against the back face of a master sheet. When typing, writing or drawing is applied to the master, a reversed or mirror image is formed by the carbon sheet on the back face of the master sheet.

Prior to the present invention it has been customary practice to combine the master sheet and the carbon sheet in a simple master set. The set usually comprised a master and a carbon in face-to-face relationship and joined together at one end. A serrated tear line on the master sheet and/or the carbon sheet near the joined end permitted the carbon and, master to be separated after the mirror image had been placed on the master.

The prior master set combinations had many shortcomings. For example, the transfer sheet was usually completely coated from edge to edge. The carbon coating had a tendency to bleed from the edges of the carbon sheet onto the edges of its respective master, and when the master sets were stacked one upon the other in normal packaging, onto the edges of adjacent master sheets in the stack. This superfluous carbon adheres to the edges and margins of the printing face of the master sheet, so that when copies are made from these masters, it is dissolved onto the spirit-moistened copy sheets, marring the appearance of the copies.

Among'other ditficulties involved in the use of prior types of master sheet set was that the user had to grasp the coated surface of the carbon sheetin order to separate it from the master sheet, thereby soiling his hands, and creating the hazard of smudging the master.

Another difiiculty with the former master sets, was involved in the filing of a used master sheet for possible future use. The carbon images on the master sheets were exposed so that they might be blurred by rubbing of the master sheets against adjacent surfaces in the file.

' 'Among the objects of the present invention is that of providing a master sheet set which permits easy detachment of the transfer sheet without the necessity of touching any of the coated portions of the carbon sheet, and

which substanitally eliminates the possibility of smudging the master.

Another object is that of providing a master set which is simple and economical in construction and easy to use. Although in the accompanying drawings a preferred embodiment of the present invention is shown and the same is described-in detail in this specification, it is to be understood that this embodiment is not intendedt'o be 2,925,033 Patented Feb. 16, 1950 either exhaustive or limiting of the invention, but, on the contrary, is chosen for the purpose of illustrating the invention in order that others skilled in the art may so fully understand the invention, its principles and the application thereof, that they may embody it and adapt it in numerous forms, each as may be best suited to the requirements of its particular use.

In the drawings:

Figure 1 is a perspective view of a master sheet set embodying features of the present invention, with fragmentary'cut away portions showing the relationship of the various components;

Figure 2 is a side view of the master sheet set;

Figure 3 is another side view of the master sheet set to which an interleaving protective sheet or slip sheet has been added;

Figure 4 is a side view of the master set with the carbon sheet and the backing sheet stub detached from the remainder of the set;

Figure 5 is a perspective plan view showing the master sheet and backing sheet in an open, unfolded position;

Figure 6 is a perspective view of the master sheet and backing sheet in folded relationship;

Figure 7 is a side view of a used master set with a slip sheet placed between the master sheet and the backing sheet.

Referring to Figure l, a master sheet 12 and a backing sheet 14 are formed from a unitary sheet of paper by folding said sheet along a scored or serrated line 16.

The backing sheet 14 has a transverse serrated line 18 across its free end portion forming a stub 20. A carbon sheet 22 is fixedly attached at one end 24 to the stub 20. The carbon sheet 22 is positioned so that its coated face is toward the master 12.

When writing 26 or any similar impression is made on upper face of the master 12, a spirit carbon mirror image 28 is placed on the under face of the master sheet by the coated face of the carbon sheet 22 as shown at 28 in Figures 5 and 6..

Advantageously the coating of the carbon sheet 22 is terminated along lines 30 spaced from the edges 32 of the sheet 22 to leave uncoated marginal portions 34. A slip sheet 36 is inserted between the master 12 and the carbon sheet 22. This slip sheet 36, in combination with the uncoated margins 34 of the carbon sheet effectively prevents any smudging of the master, either due to pressure applied to the master set in handling or due to bleeding of carbon onto the edges of the master.

The carbon sheet 22 as shown in Figures 1 and 2 ends short of the fold line 16. When it is desired to detach the carbon sheet the user holds the stub 20 in one hand and the ends of the master and backing sheets in the other. A quick pull tears the assembly along the serrated line 18 and separates the stub 20 and the attached transfer sheet 22 from the backing sheet 14. This may be done without touching the carbon sheet at all, thus detaching the master 12 ably attached on the serrated line 16. sheet'thus protects the carbon image on the back of the master 12 until it is ready for use. To make copies, the master is folded back along line 16 to the position shown in Figure 6. The carbon image 28 now faces outwardly, and the master may thus be placed on a duplicating machine and thedesired number of copies made.

After the copies have been made, the master may be filed for future use if desired. To protect the carbon image during storage, the master sheet 12 is folded back along line 16 to the position shown in Figure 7 so that the face bearing the carbon, image is toward the backing sheet 14. If desired the slip sheet 36 may be The backing and the backing sheet 14 fold-.

reinserted, as shown in i igiife I, or the master may be stred with the mirror image firteted by the bakiflg sheet 14 alone.

It will thus be seen that the present inyention provides a master sheet set s6 censt'ruet'ed. that thetfidss'ibilitiesl of s'mudgin the master of, soiling" theharids 6f the use? are Substantially eliminateda This has been acdr'ii'plishe'd' without substantial increases" in mantlfaetilriri'g c'cis tf or complexities of operation.

I claim: a

A spirit duplicating master set comprising. arhas'ter sheet, a backing sheet, a slip sheet and a carbon sheet,

said master and backing sheets being; formed from aunitary pieceof paper with a fold; line defining. said. sheets, said sheets being" foldable about said. line, said backing sheet having a, transversestear line near; ts 613150- site edge to term a riarrew detach-able stub, said. stiib extending beyond the edge of said master sheet, the Itin-v gitudinal extent Of said backing sheet between said tear' and fold lines being less than the longitudinal; eitent: of 20 said master sheet, said carbon sheet being pdsitidned be tween said master and backing sheets with the cdat'edv fi mness face; of said-earbenshe'et towardssaid mister sheet, sald,

edated face of the carbon sheet having uncoated longitudinal margin portions extending along the longitudinal edges of said carbon sheet, said slip sheet cooperatively interposed between said master sheet and the coated face of said carbon sheet, andone transverse edge portion of said carbon sheet being attached to said detachable stub and the opposite edge of said carbon sheet being near to but away from thefold line defining said master and backing sheets whereby portions of said master and backing sh'ets-- are in td'ucliable felaition'sliifi fiear's'aid fold line. i

I lieferencescitedin.the tile of this patent L Ada-L 

